getting two different battery readings help plz!!

[rob_956]

Hello,

changed water pump on my 03 jeep liberty and after that stinger voltage is reading 12.5 for the back battery and the battery in the front is reading 13.8 what is going on.checked both batteries with a fluke

Help please!!

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[rob_956]

Heeeelp

 

[jco1385 5,000+ posts]

Sounds like the rear battery is at resting voltage. Did you reconnect it to the wiring to the alt?

 

[Jepalan]

Do you have one or two alternators? If two, did you get the belt back on the 2nd one?

 

[marcos65]

Not enough information.

 

[rob_956]

I have one alt one battery up front and a rear one yes everything is connected double checked i dnt know whats wrong

Thankz guyz

 

[rob_956]

When playing music in the front it reads 13.8 drops to 12.6 or so

Back battery reads 12.5 and drops to bout 12.0 its weird

 

[Jeffdachef 5,000+ posts]

When playing music in the front it reads 13.8 drops to 12.6 or soBack battery reads 12.5 and drops to bout 12.0 its weird

There's a break in the connection somewhere the rear battery is simply not connected OR your grounding point does not work, move it.

 

[Full Tilt 10+ year member]

There's a break in the connection somewhere the rear battery is simply not connected OR your grounding point does not work, move it.

Clearly the rear battery is connected if it's dropping.

 

[Jeffdachef 5,000+ posts]

Clearly the rear battery is connected if it's dropping.

rear battery should charge very close to the same voltage as front battery there's a lot of resistance going on somewhere.

 

[rob_956]

It was charging same as the front battery drop the same but since i changed the water pump it started to do this

 

[rob_956]

I jus tripled check the wires everything is fine rear battery is hooked up can it be the serpentine belt slipping??

Thankz guys anyways

 

[jco1385 5,000+ posts]

Belt slip would make both read low because the alt would not put out what it should. A water pump has nothing to do with this. Something you messed with while doing the water pump is the issue. Sounds like a lot of resistance somewhere (ground?), or a bad battery.